1. Field of the Invention
This invention relates broadly to medical instruments. More particularly, this invention relates to an umbilical cord blood extractor which extracts placental blood from a cut section of umbilical cord.
2. State of the Art
The umbilical cord serves as the conduit between a mother and a fetus developing in the womb of the mother. Nutrients and oxygen within the blood of the mother pass through the umbilical cord to the fetus. Immediately after a baby is born, the umbilical cord is clamped to stop the flow of blood through the umbilical cord. The umbilical cord is then cut to free the baby from the placenta.
In accord with standard medical procedure, after birth, the blood from the umbilical cord is sampled, and chemical and biological assays are performed on the blood. The assays are used to determine whether a potential mismatch exists between mother and baby blood types and whether the baby is subject to potential genetically transmitted diseases, bacterial diseases, and viral infections, such as human immunodeficiency viruses which lead to AIDS and hepatitis B and C. Generally, it is desirable to recover the cord blood sample quickly and safely given the time and health concerns of the practitioner within managed health care systems.
A quick method of sampling blood from the cord is to manually milk blood from the section of cut cord; i.e., to squeeze the section of cut umbilical cord by hand to rapidly and thoroughly remove blood from the cord. However, this is not usually practical. The umbilical cord is coated with various fluids, e.g., vaginal blood, amniotic fluid and Wharton's gel, making the cord slippery and hard to handle. Furthermore, it is desirable to minimize contact between health care workers and such fluids. In fact, federal law and an association of operating room nurses have mandated protecting health care workers from blood born pathogens.
A number of devices have been disclosed for taking a sample of blood from an umbilical cord which do not require manually milking the cord. U.S. Pat. No. 5,575,795 to Anderson discloses an umbilical cord holder having an elongate portion with a curved open trough and clamps at either end of the elongate portion. A health care worker places the umbilical cord into the trough and seals the ends of the umbilical cord with the clamps. While holding the elongate portion, the practitioner inserts a needle through the open trough and into the cord and a syringe is operated to withdraw blood from the cord. However, this device has several drawbacks. First, the device requires the use of two hands to extract blood, one to hold the elongate portion and one to operate the needle and syringe. Second, the device requires the use of a needle which must be inserted through the open trough and into the cord. As a result, there exists the potential for unintentional needle pricking, and exposure to blood borne pathogens such as HIV and hepatitis. Third, the blood collected in the syringe must then be transferred from the syringe to one or more vials, which creates an additional risk of unintentional pricking. Fourth, the procedure to extract blood from the cord using this device is substantially time consuming.
U.S. Pat. No. 5,415,665 to Hessel et al. discloses a device which clamps, cuts, and extracts blood from an umbilical cord. The device includes a clamshell housing provided with a removable cord clamp, a cutting apparatus, and valved blood collection vials. However, the Hessel et al. device does not provide a safe method for removing blood. The device must be hand held while cutting the cord and during the collection the blood. Therefore, during cord cutting and blood collection the likelihood of contact between the practitioner and blood is not minimized. In addition, the device is relatively complex and, seemingly relatively difficult to manufacture.
U.S. Pat. No. 5,342,328 to Grossman et al. discloses an alternative to Hessel. The device is a cup having a lower blood reservoir. A cut section of umbilical cord is placed into the cup and allowed to gravity drain into the reservoir. Once the blood has drained, the blood is then transferred to a vial. Very little handling of the cut cord is required once the cord is in the cup. However, the design of the Grossman et al patent requires the gathering of a large section of umbilical cord, as blood is not squeezed from the cord member as in the manual method, or directly extracted by needle and syringe as in Anderson. In addition, the system requires waiting for the blood to drain into the blood reservoir, making it highly impractical given the time concerns mandated by managed health care.